Heat exchanger

ABSTRACT

A heat exchanger includes a core unit having a plurality of pipe members arranged in parallel, a pair of tanks joined to the core unit to sandwich the core unit from opposite sides in a longitudinal direction of the pipe members and communicating with the pipe members, and a partition plate for closing a cross-section of the tank. The partition plate includes a recess on an outer edge portion to be held in contact with an inner wall surface of the tank, the tank includes a projection to be engaged with the recess on the inner wall surface, and the projection and the recess are formed by plastic working a part of the tank in contact with the partition plate from an outer side toward an inner side of the tank in a state where the partition plate is arranged in the tank.

TECHNICAL FIELD

The present invention relates to a heat exchanger.

BACKGROUND ART

A heater core to be incorporated into an air conditioner is known as a heat exchanger used in an automotive vehicle. JP2000-304488A discloses a heater core which includes a core unit composed of a plurality of tubes arranged in parallel and a pair of tanks arranged to sandwich the core unit at opposite longitudinal ends of the tubes and in which a tank interior is partitioned by a partition plate.

The tank of the heat exchanger described in the above literature is a so-called combined tank composed of a core plate connected to the core unit and a tank plate defining a tank internal space by being combined with the core plate. The partition plate is positioned by engaging projecting pieces provided on the partition plate with notches provided on each of the core plate and the tank plate. The projecting pieces exposed to the outside of the tank by penetrating through the notches of the core plate and the tank plate are squeezed by press-working at the time of molding the tank, thereby closing clearances between the notches and the projecting pieces. In this way, the leakage of fluid flowing in the tank to the outside is prevented.

SUMMARY OF INVENTION

It is effective to thin each member in order to make the heat exchanger lighter and reduce material cost. However, if the partition plate is thinned in the above configuration, it becomes difficult to close the clearances between the notches and the projecting pieces due to deformed parts by press-molding, wherefore cooling liquid flowing inside may leak to the outside.

Accordingly, the present invention aims to provide a tank capable of preventing leakage even if a partition plate is further thinned.

According to one aspect of the present invention, a heat exchanger is provided which includes a core unit including a plurality of pipe members open at opposite ends and arranged in parallel, a pair of tanks joined to the core unit to sandwich the core unit from opposite sides in a longitudinal direction of the pipe members and communicating with the pipe members; and a partition plate for closing a cross-section of the tank intersecting with a pipe member arrangement direction. The partition plate of the heat exchanger includes a recess on an outer edge portion to be held in contact with an inner wall surface of the tank, the tank includes a projection to be engaged with the recess on the inner wall surface, and the projection and the recess are formed by plastic working a part of the tank in contact with the partition plate from an outer side toward an inner side of the tank in a state where the partition plate is arranged in the tank.

According to the above aspect, since the partition plate is positioned with respect to the tank by the engagement of the projection and the recess and the part deformed by plastic working does not project outwardly of the tank, there is no possibility that cooling liquid leaks to the outside of the tank even if the partition plate is further thinned for a weight reduction.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an overall configuration diagram of a heat exchanger according to an embodiment of the present invention,

FIG. 2 is a perspective view enlargedly showing a part A of FIG. 1,

FIG. 3 is an exploded view of the part shown in FIG. 2,

FIG. 4A is a sectional view showing a temporarily assembled state of a tank,

FIG. 4B is a sectional view after press-working,

FIG. 5 is a sectional view along V-V of FIG. 4,

FIG. 6 is a sectional view along VI-VI of FIG. 4,

FIG. 7 is a sectional view along VII-VII of FIG. 4, and

FIG. 8 is a sectional view along VIII-VIII of FIG. 4.

DETAILED DESCRIPTION

Hereinafter, an embodiment of the present invention is described with reference to the accompanying drawings.

FIG. 1 is an overall configuration diagram of a heat exchanger 1 according to an embodiment of the present invention. This heat exchanger 1 is used, for example, as a heat exchanger for heating, i.e. a so-called heater core, to be installed in a vehicle and formed by brazing and joining each member made of aluminum alloy. Brazing and joining are performed by applying a brazing material to a surface of at least one of members to be held in contact with each other in advance and introducing the members in an assembled state into a furnace and heating them. It should be noted that each member is described in detail later.

The heat exchanger 1 includes a core unit 7 composed of a plurality of pipe members 3 open at opposite ends and arranged in parallel and corrugated fins 4 sandwiched between adjacent ones of the pipe members 3, and a pair of tanks 2A, 2B joined to sandwich the core unit 7 from opposite sides in a longitudinal direction of the pipe members 3 and communicating with the pipe members 3.

A supply flow passage 5 for supplying cooling liquid to the heat exchanger 1 and a discharge flow passage 6 for discharging the cooling liquid from the heat exchanger 1 are connected to one tank 2A. Further, although not shown in FIG. 1, the tank 2A includes a partition plate 12 for closing a cross-section of the tank 2A intersecting with a pipe member arrangement direction. The shape and positioning of the partition plate 12 are described later.

The partition plate 12 is arranged, for example, between a part of the tank 2A connected to the supply flow passage 5 and a part thereof connected to the discharge flow passage 6. Here, for the sake of convenience, a side connected to the supply flow passage 5 is referred to as an inlet side and a side connected to the discharge flow passage 6 is referred to as an outlet side out of spaces partitioned by the partition plate 12 in the tank 2A.

By arranging the partition plate 12 as described above, the cooling liquid supplied from the supply flow passage 5 flows into the tank 2B via each pipe member 3 connected to the inlet side of the tank 2A, moves in the tank 2B, returns to the outlet side of the tank 2A via each pipe member 3 connected to the outlet side of the tank 2A and is discharged via the discharge flow passage 6. The cooling liquid is mainly cooled by a heat exchange with the pipe members 3 while flowing in the pipe members 3.

FIG. 2 is a perspective view showing a part A of FIG. 1, i.e. a part of the tank 2A where the partition plate 12 is arranged. FIG. 3 is a perspective view of the same part as in FIG. 2.

The tank 2A includes a core plate 10 to be joined to the core unit 7, a tank plate 11 to be joined to the core plate 10 and the partition plate 12 for dividing a tank space formed by the core plate 10 and the tank plate 11.

The core plate 10 includes a bottom portion 10B in which a row of openings 10A, through which the pipe members 3 are inserted, is provided, and a pair of wall portions 10C arranged at opposite sides of the row of the openings 10A in a direction perpendicular to an arrangement direction of the openings 10A and extending in a direction opposite to the core unit 7 from the bottom portion 10B. That is, the core plate 10 is a member having a substantially U-shaped cross-section perpendicular to the arrangement direction of the openings 10A.

The tank plate 11 is joined to the pair of wall portions 10C to form the tank space together with the core plate 10.

The partition plate 12 is arranged to close the cross-section of the tank 2A perpendicular to the arrangement direction of the openings 10A in order to divide the tank space formed by the core plate 10 and the tank plate 11.

A first projecting portion 12A is provided on an edge portion of the partition plate 12 to be held in contact with the tank plate 11 and this first projecting portion 12A is engaged with an engaging hole 11A provided on the tank plate 11. Further, a pair of second projecting portions 12B is provided on edge portions of the partition plate 12 facing the pair of wall portions 10C, and this pair of second projecting portions 12B are engaged with a pair of cut portions 11B provided on the tank plate 11.

The above tank plate 11 and partition plate 12 are positioned with respect to the core plate 10 by later-described projections 13 provided on the pair of wall portions 10C.

It should be noted that opposite end parts of the tanks 2A, 2B may be closed by end plates similar to the partition plate 12, or the core plate 10 or the tank plate 11 may be molded into a channel with closed opposite ends.

Next, the procedure of forming the tank 2A is described.

FIGS. 4A and 4B are both a sectional view along IV-IV of FIG. 2 (sectional view including a part into which a punch 14 is to be driven), wherein FIG. 4A shows a state where the core plate 10, the tank plate 11 and the partition plate 12 are temporarily assembled and FIG. 4B shows a state where the projections 13 are formed by plastic deformation.

As shown in FIG. 4A, stepped portions 20 on which the second projecting portions 12B of the partition plate 12 are to be seated are provided on surfaces of the pair of wall portions 10C facing each other.

The temporarily assembled state is such a state where the partition plate 12 and the tank plate 11 with the first projecting portion 12A and the engaging hole 11A of the tank plate 11 engaged and with the pair of second projecting portions 12B and the cut portions 11B of the tank plate 11 engaged are so assembled with the core plate 10 that the second projecting portions 12B are seated on the stepped portions 20.

It should be noted that although the first projecting portion 12A of the partition plate 12 is merely engaged with the engaging hole 11A of the tank plate 11 in this embodiment, the first projecting piece 12A may be plastically deformed at an outer side of the tank plate 11 and the partition plate 12 may be held in close contact and temporarily fixed so as not to be disengaged from the engaging hole 11A.

If the temporarily assembled state is reached, the punch 14 is driven from an outer side toward an inner side of the tank 2A into parts of the wall portions 10C in contact with outer edge portions of the second projecting portions 12B in a projecting direction. The punch 14 used has, for example, a spherical tip and a diameter equal to or smaller than a plate thickness of the partition plate 12.

In this way, the parts of the core plate 10 where the punch 14 is driven are plastically deformed, the projections 13 convex in a direction toward the inner side of the tank 2A are formed and recesses 15 to be engaged with the projections 13 are formed on the outer edge portions of the second projecting portions 12B.

After the projections 13 and the recesses 15 are formed in the above manner, the core plate 10, the tank plate 11 and the partition plate 12 are brazed. In this way, the tank 2A is formed.

FIG. 5 is a sectional view along V-V of FIG. 4B and FIG. 6 is a sectional view along VI-VI of FIG. 4B.

As shown in FIGS. 5 and 6, the projections 13 formed on the core plate 10 and the recesses 15 formed on the partition plate 12 by driving the punch 14 are engaged with each other and the projections 13 are also engaged with the cut portions 11B of the tank plate 11.

FIG. 7 is a sectional view along VII-VII of FIG. 4A and FIG. 8 is a sectional view along VIII-VIII of FIG. 4B.

If a vertical direction of FIGS. 7 and 8 is a width direction of the cut portions 11B and a thickness direction of the partition plate 12, B denotes a width of the cut portions 11B before the punch 14 is driven and A denotes a thickness of the second projecting portions 12B of the partition plate 12 before the punch 14 is driven, a relationship where the width B is larger than the thickness A is satisfied as shown in FIGS. 7 and 8. That is, in the temporarily assembled state before the punch 14 is driven, there are clearances between the cut portions 11B and the second projecting portions 12B of the partition plate 12. However, when the punch 14 is driven, the second projecting portions 12B are plastically deformed to increase the thickness A and fill up the clearances to the cut portions 11B. That is, the core plate 10, the tank plate 11 and the partition plate 12 are integrated.

It should be noted that although a case where only one partition plate 12 is arranged in the tank 2A is described here, the partition plates 12 are similarly fixed by driving the punch 14 also when two or more partition plates 12 are provided. Further, when two or more partition plates 12 are arranged in the tank 2A, partition plates 12 are also arranged in the tank 2B. Also in this case, a configuration for fixing the partition plates 12 is similar.

Next, effects obtained by configuring the tank 2A as described above are described.

(1) In the heat exchanger 1 of the present embodiment, the partition plate 12 includes the recesses 15 on parts to be held in contact with an inner wall surface of the tank 2A and the tank 2A includes the projections 13 to be engaged with the recesses 15. The projections 13 and the recesses 15 are formed by driving the punch 14 into the parts of the tank 2A held in contact with the partition plate 12 from the outer side toward the inner side of the tank 2A with the partition plate 12 arranged in the tank 2A. Specifically, the partition plate 12 is positioned in the tank 2A by the engagement of the projections 13 and the recesses 15. Since the deformed parts of the partition plate 12 by the driving of the punch 14 do not project outwardly of the tank 2A, the cooling liquid does not leak from the clearances between the partition plate 12 and the wall surface of the tank 2A even if the partition plate 12 is further thinned.

(2) In the present embodiment, the tank 2A includes the core plate 10 and the tank plate 11, the tank plate 11 includes the pair of cut portions 11B and the partition plate 12 is engaged with the cut portions 11B. The recesses 15 are formed on the parts of the partition plate 12 to be engaged with the cut portions 11B. In this way, the partition plate 12 is positioned with respect to the tank plate 11 by being engaged with the cut portions 11B and positioned with respect to the core plate 10 by the engagement of the projections 13 and the recesses 15. Further, the projections 13 formed by driving the punch 14 are also engaged with the cut portions 11B.

Specifically, the partition plate 12 is positioned with respect to the core plate 10 by driving the punch 14 to form the projections 13 and the recesses 15 and, simultaneously with this, the tank plate 11 is also positioned with respect to the core plate. Thus, according to the present embodiment, steps required to assemble the tank 2A can be simplified and a cost reduction can be realized.

Further, since the punch 14 is driven into the parts of the core plate 10 held in contact with the partition plate 12, the deformation of the tank 2A caused by the driving of the punch 14 is suppressed and stable brazing can be performed.

(3) In the present embodiment, the parts of the partition plate 12 to be engaged with the cut portions 11 serve as the second projecting portions 12B projecting in a direction toward the wall portions 10C and the core plate 10 is provided with the stepped portions 20 on which the second projecting portions 12B are to be seated. This can prevent the rotation of the partition plate 12 and the tank plate 11 about the arrangement direction of the openings 10A with respect to the core plate 10 in the tank 2A in the temporarily assembled state before the punch 14 is driven and enables the tank 2A to be accurately assembled.

(4) In the present embodiment, the tank plate 11 includes the engaging hole (through hole) 11A on a line connecting the pair of cut portions 11B and the partition plate 12 includes the first projecting portion (engaging portion) 12A to be engaged with the engaging hole 11A. This causes the partition plate 12 to be more reliably positioned with respect to the tank plate 11.

Although the embodiment of the present invention has been described above, the above embodiment is merely one application example of the present invention and not of the nature to limit the technical scope of the present invention to the specific configuration of the above embodiment.

The present application claims a priority of Japanese Patent Application No. 2014-57878 filed with the Japan Patent Office on Mar. 20, 2014, and Japanese Patent Application No. 2015-24475 filed with the Japan Patent Office on Feb. 10, 2015, all the contents of which are hereby incorporated by reference. 

1. A heat exchanger, comprising: a core unit including a plurality of pipe members open at opposite ends and arranged in parallel; a pair of tanks joined to the core unit to sandwich the core unit from opposite sides in a longitudinal direction of the pipe members and communicating with the pipe members; and a partition plate for closing a cross-section of the tank intersecting with a pipe member arrangement direction, wherein: the partition plate includes a recess on an outer edge portion to be held in contact with an inner wall surface of the tank; the tank includes a projection to be engaged with the recess on the inner wall surface; and the projection and the recess are formed by plastic working a part of the tank in contact with the partition plate from an outer side toward an inner side of the tank in a state where the partition plate is arranged in the tank.
 2. The heat exchanger according to claim 1, wherein: the tank includes a core plate composed of a bottom portion with a row of openings, through which the pipe members of the core unit are inserted, and a pair of wall portions arranged to sandwich the row of the openings in a direction perpendicular to an arrangement direction of the openings and extending in a direction opposite to the core unit from the bottom portion, and a tank plate joined to the pair of wall portions to form a tank space together with the core plate; the tank plate includes a cut portion on each of a pair of edge portions to be joined to the pair of wall portions; the partition plate is engaged with the cut portions; and the recesses are formed in parts of the partition plate to be engaged with the cut portions.
 3. The heat exchanger according to claim 2, wherein: the parts of the partition plate to be engaged with the cut portions serve as a pair of projecting portions projecting toward each of the pair of wall portions; and the core plate includes stepped portions on which the projecting portions are to be seated.
 4. The heat exchanger according to claim 2, wherein: the tank plate includes a through hole on a line connecting the pair of cut portions; and the partition plate includes an engaging portion to be engaged with the through hole. 